In pledges made by the party ahead of May’s Assembly election they also promised to slash #100-a-year off pensioners’ council tax bills.

The initiative would see householders swap power-sapping conventional bulbs for #20-worth of greener lights.

The “bulb amnesty” drive against climate change is being announced by the party’s Assembly leader, Nick Bourne.

The environmental initiative would cost taxpayers #24.8m over four years if everyone took it up.

The Tories also promised to commit #30.95m to help older people meet the cost of rising council tax bills. Up to 309,500 pensioner homes in Wales could qualify for the reduction – those hit hardest by rising council tax bills and council tax revaluation.

The policies were unveiled as the Welsh Conservative Party gathers for its conference in Cardiff.

The run-up to the May 3 election has seen the Tories come under an onslaught from Labour critical of 18 years of “Tory rule” from the 1980s.

The new election slogan – Vote Welsh Conservative for a Change – aims to reflect the shift in the party under leader David Cameron, who will address the conference tomorrow.

Mr Bourne, who makes a keynote speech to the conference today, said: “Climate change is one of the greatest challenges facing us today but we can only tackle it if we all act together.”

The light bulbs were identified as a practical measure that every home could take to reduce the CO2 emissions blamed for global warming.

The promises would be funded from a #145m election spending plan, funded by 1% efficiency savings in the Assembly’s #14.5bn budget, if they formed the next government in Cardiff Bay.

It also included #20m to fund modern medicines, #10m for hospices, #16m for affordable homes and #2m for the air ambulance service.

Council tax payers in Wales will see bills rise by more than those in England from April when the average bill for a band D property in Wales goes up by 4.7%, 0.5% more than in England.

Average council tax bills have almost doubled in Wales between 1997 and 2006, rising from #496 to #962 for a band D property.

Mr Bourne said: “Pensioners and those on fixed incomes have been hit hardest of all by the massive council tax rises we have seen under Labour.

“As a party we are determined to get council tax back to sustainable levels, restore confidence in the system and help those on fixed or low incomes.”

Mr Bourne was expected to tell the conference: “Our focus is clearly our environment, families, communities, the NHS and the Welsh language.

“Welsh Conservatives have changed and with the support of the public we can bring about a change of Government and a new direction for Wales.”

A Welsh Labour spokesman said: “People in Wales know they can’t trust the Tories with local tax. In the final year of Tory rule in 1997, council tax rose on average by 18%. This year with Labour it will be less than 5%.”